Electron Flow Research Articles

High-Current Capability and Upgrades of the EBIS/T Charge-Breeding System in the Reaccelerator at the Facility for Rare-Isotope Beams

The Reaccelerator (ReA) of the Facility for Rare-Isotope Beams (FRIB) at Michigan State University uses a Beam Cooler/Buncher (BCB) and an Electron-Beam Ion Trap (EBIT) as a charge-breeding injector system. The rare isotopes produced by In-flight Separation are selected by the Advanced Rare Isotope Separator (ARIS) and stopped in a helium gas cell. Long-lived and stable-isotope beams can also be extracted from a Batch-Mode Ion Source (BMIS). The continuous beams transported at low energy to ReA are injected into the BCB. The pulsed beams are then injected into the EBIT, charge bred, ejected, and accelerated by ReA’s LINAC. The EBIT electron current (300 - 600 mA) is a factor that limits its capacity to ∼2×1010 elementary charges, which restricts the maximum EBIT-extracted rates to less than 2×1010 particles per second for light ions. An upgrade of the EBIT electron gun is expected to provide 2 A in current. In parallel, a High-Current Electron-Beam Ion Source (HCEBIS) is being commissioned. The HCEBIS can presently provide an electron current of 2 A. An upgrade will increase the current to 4 A. The implementation of these two upgrades is expected to allow for maximum rates to be ∼1011 pps, compatible with FRIB projected rates and user demands. We review the high-current capabilities and upgrades of ReA’s charge-breeding system.

Abstract 1036: Mechanisms Of Foamy Monocyte Formation In Atherosclerosis

Diseases linked to atherosclerosis are the leading cause of death in the United States. Transmigration of monocytes across the endothelial layer and their differentiation into macrophages play an important role in the initiation and progression of atherosclerosis. These monocyte-derived macrophages internalize modified LDL in the arterial wall and drive the pathogenesis of atherosclerosis. Recent studies have shown that pharmacological depletion of foamy monocytes inhibits atherosclerosis development in mice, identifying monocyte uptake of plasma LDL as a therapeutic target in atherosclerosis. However, the precise mechanisms by which monocytes internalize plasma LDL remain unknown. The goal of our study was to investigate the role, and relative contribution, of macropinocytosis and scavenger receptors ( Cd36 and Sr-a ) to foamy monocyte formation. The presence of foamy monocytes was confirmed in hypercholesterolemic mice and humans via flow cytometry analysis of Nile Red fluorescence. High resolution scanning electron microscopy and flow cytometry analysis of dextran internalization confirmed macropinocytosis stimulation in THP-1 and primary murine monocytes. Stimulation of macropinocytosis in monocytes induced uptake of both native LDL and oxLDL, leading to foamy monocyte formation in vitro . Pharmacological (EIPA) and genetic inhibition of macropinocytosis ( Lysm - CreER T2+/- Nhe1 -/- ) inhibited foamy monocyte formation (58.9%) in hypercholesterolemic mice in vivo . RT-PCR confirmed expression of Cd36 and Sr-a in monocytes and deletion of Cd36 and Sr-a inhibited foamy monocyte formation in hypercholesterolemic mice (10.3%) compared to wild type controls. FACS and bulk RNA sequencing characterized monocyte subsets including classical, intermediate, and non-classical monocytes in hypercholesterolemic Cd36 -/- / Sr-a -/- and Lysm - CreER T2+/- Nhe1 -/- mice and their respective wild type controls. Mechanistic studies identified NADPH oxidase 2 (Nox2) and downstream redox regulation of actin-cytoskeleton as a major stimulator of monocyte macropinocytosis. These results provide novel insights into the mechanisms of foamy monocyte formation and potentially identify new therapeutic targets in the treatment of atherosclerosis.

Numerical characterization of capacitively coupled plasma driven by tailored frequency modulated radio frequency source

Capacitively coupled plasma (CCP) is widely used in plasma etching and deposition processes because of its low cost, simple structure, and easy generation of a uniform plasma in large areas. Conventional CCPs are operated under a fixed frequency power source; however, CCPs driven by a variable frequency power source are poorly understood. In this paper, numerical simulations of CCPs driven by frequency modulated (FM) radio frequency (RF) sources within the frequency range of 2 MHz–18 MHz are carried out with a particle-in-cell/Monte Carlo collision model. Our research indicates that the CCP driven by an FM RF source can maintain a stable glow discharge and form a time-dependent plasma. Plasma density, electron and ion current, energy and heating rate, ion flux, and energy on the electrodes fluctuate consistently with the FM period. The electron and ion energy distribution function can also be modulated by the frequency variation of the FM source. A multi-peak structure that varies and shifts with frequency variation is observed in the ion energy distribution function. In addition, by fixing the chirp period while varying the start or end frequency of the chirp signal (start frequency from 0.4 to 6 MHz, or end frequency from 18 to 48 MHz), effective modulations can be produced on the electron density, electron energy, and the shape of the EEPF and IEDF.

The commoditization of civil nuclear power.

The commoditization of nuclear power through the factory production of sealed micro-power units within a digitally enabled holistic assurance framework is described. This would revolutionize nuclear power-plant design, construction, operation and decommissioning through a paradigm shift to manufacture-operate-remove-recycle (MORR). The potential impact of recent research on an integrated nuclear digital environment for large bespoke nuclear power plants and the design, build and operation of fusion power plants using such a digital environment is explored. These strands are interwoven to discuss the technical, economic and socio-political implications of MORR in the context of micro-reactors and to consider the potential evolution of safeguarding issues based on a digital assurance framework that leads to type approvals. Commoditization of nuclear power would lower costs in line with offshore wind and the output from a single production line in a factory could replace a third of current fossil fuel-based electricity generation in the UK over a 15-year period, making a significant contribution to achieving zero greenhouse gas emissions. The challenges associated with the changes in culture, both in the nuclear industry and in society, as well as the technology gaps, that need to be addressed in realizing this paradigm shift are identified and discussed.

Enhanced photocatalytic hydrogen generation using UiO-66(Zr) MOF with tailored modifications: A review

The utilization of UiO-66 MOF-based photocatalytic materials has achieved significant attention for their potential in hydrogen generation, owing to their remarkable stability and porous crystalline structure. Recent studies have disclosed enhanced light absorption capabilities in UiO-66 through both pre and post-synthetic modifications. These modifications also play a significant role in mitigating the recombination of photogenerated charge carriers by facilitating electron transfer in hybrid or derived materials. Designing of MOF-based modified improved photocatalyst includes, integration with other low band gap semiconductors, incorporation of noble metals as co-catalysts, surface engineering, inclusion of defects or introduction of heteroatom in the framework. MOF-COF hybridization, dye sensitization etc., further reinforced photocatalytic hydrogen yield. The above-mentioned comprehensive investigations have researched into aspects such as morphology, hydrogen generation efficiency, and the underlying mechanisms. It reveals that the creation of heterojunctions at interface channelizes the separation and smooth flow of electrons resulting in suppression of recombination reaction and favorable photocatalytic properties. The synergy between the components often results in enhanced performance. The present article provides a comprehensive review of modified UiO-66 MOF-based materials investigated for photocatalytic hydrogen generation.

On the two-dimensional Brillouin flow

The Brillouin flow is a rectilinear, sheared electron fluid flow in a crossed electric field (E) and magnetic field (B), in the E × B direction with zero flow velocity and zero electric field at the surface with which the flow is in contact. It is broadly considered as the equilibrium electron flow in high power crossed-field devices including the magnetron and magnetically insulated transmission line oscillator. This paper provides an examination of Brillouin flow in two dimensions, in a cylindrical geometry where the anode radius changes abruptly at a single axial location, while the cathode surface has a constant radius. Our simulation confirms the proof that there is no equilibrium Brillouin flow solution for such a geometry. It further reveals that this change in the anode radius introduces novel bunching of the electrons within the Brillouin hub. This bunching occurs at low frequencies and is very pronounced if the Brillouin flow is from the small gap region to the large gap region, but is minimal if the Brillouin flow is from the large gap region to the small gap region. New insights are provided into the physical processes that initiate and sustain the bunching processes that are unique for a crossed-field diode, as compared with a non-magnetized diode. We argue that this enhanced bunching, and its concomitant formation of strong vortices, is not restricted to an abrupt change in the anode–cathode gap spacing.

Development and calibration of a multi-delay coherence imaging diagnostic on the MAST-U tokamak.

The MAST-U Super-X divertor provides the opportunity to study fusion plasma exhaust under novel conditions. However, in order to study these conditions, advanced diagnostics are required. Following the development of the MAST-U Multi-Wavelength Imaging (MWI) diagnostic, we present the installation of a multi-delay coherence imaging spectroscopy (CIS) system within the MAST-U MWI, along with modifications made to the MWI for effective operation. This diagnostic will measure either carbon ion flow velocities and temperatures or electron densities through Dγ emission. We have extended previously developed techniques for wavelength calibration to account for errors due to the misalignment of interferometer components. In addition, we have developed a comprehensive calibration procedure to account for the temperature dependence of the instrument's delays by fitting to a linearly modified version of the delay equation presented by Veiras etal. [Appl. Opt. 49(15), 2769 (2010)]. Together, these procedures reduce the cost and hardware complexity of implementing CIS instruments when compared to those that use in situ or tunable laser calibration systems, as calibrations can be generated to good accuracy using previously measured data.

Solar wind effect on the multi-fluid plasma expansion in the Venusian upper ionosphere

Inspired by the observations suggesting that at altitudes of about 1000 km the interaction between solar wind streams and Venus’ ionosphere plasma leads to ions acceleration and outflow, the influence of different solar wind physical parameters, such as densities, temperatures and initial streaming velocities, has been studied. The ionosphere plasma system consists of two positive ion populations O+, H+ and electrons along with the solar wind streaming protons and electrons. We calculated the generated oxygen and hydrogen ions flow velocities and the electric fields. In addition, we calculated rough estimates for the escaping flux of ion populations (O+, H+) from Venus’ ionosphere and compared them to observations. To a large extent, we found that the estimates match. We also discuss the relevance of ionospheric ion acceleration and outflow from Venus’ upper.

Factors Influencing the Fluctuation Amplitude of the H− Ion Beam Extracted from an RF Wave Excited Ion Source Plasma

The beam oscillation of J-PARC ion source is being studied as AC electric field at 2 MHz ion source driving frequency can directly change the extraction characteristics of both H− ions and electrons. The internal RF antenna inducing the electric field generated two peaks of plasma production during one RF cycle as confirmed by 4 MHz modulation of Balmer-alpha (Hα) emission intensity. The coupling between the plasma production at 4 MHz and the oscillation of the local plasma potential in the vicinity of the extraction hole at 2 MHz can cause 6 MHz oscillation, which was observed in the measurement of extraction current from the ion source. Phase-delay of Hα intensities from the source plasma and those of the extraction electron current were compared with the RF input signal to the amplifier.

Status of the High-Current Electron-Beam Ion Source Charge Breeder for the Facility for Rare-Isotope Beams

The Reaccelerator (ReA) of the Facility for Rare-Isotope Beams (FRIB) employs an Electron-Beam Ion Trap (EBIT) as a charge breeder to reaccelerate rare-isotope beams up to 12 MeV/u. The ReA EBIT produces an electron current of 300 – 600 mA. The maximum trap capacity of the ReA EBIT is 1010 elementary charges. FRIB production rates are expected to exceed 1010 particles/s in some cases in the future. There is also a user demand for reaccelerated stable-isotope beams of more than 1010 pps. To handle these rates and provide redundancy, a High Current Electron-Beam Ion Source (HCEBIS) has been built and is now being commissioned. An electron-beam current of 2 A with a 50 % duty cycle has been transported through a 4-T field. An upcoming upgrade to increase the electron-beam current up to 4 A will allow for a maximum trap capacity of 2.4×1011 elementary charges. We present the status of the HCEBIS, including the results of the electron-beam commissioning and systematic studies.

Anomaly Detection Model of Time Segment Power Usage Behavior Using Unsupervised Learning

<p>In Taiwan, the current electricity prices for residential users remain relatively low. This results in a diminished incentive for these users to invest in energy-saving improvements. Consequently, devising strategies to encourage residential users to adopt energy-saving measures becomes a vital research area. Grounded in behavioral science, this study introduces a feasible approach where an energy management system provides alerts and corresponding energy-saving recommendations to residential users upon detecting abnormal electricity consumption behavior. To pinpoint anomalous electricity usage within specific time segments, this research employs an unsupervised machine learning method, developing an anomaly detection model for the overall electricity consumption behavior of residential users. The model focuses on analyzing 2-hour intervals of electricity consumption, enabling more effective detection of abnormal usage patterns. It is trained using power consumption data collected from five actual residential users as part of an experimental study. The results indicate that the proposed anomaly detection model achieves performance metrics such as Precision, Recall, and F1-score of 0.90 or above, showcasing its potential for practical implementation.</p> <p> </p>

EVALUATING THE SAFETY AND THERAPEUTIC EFFICACY OF INTRAVENOUS HYDROGEN NANOBUBBLE INFUSIONS IN A HYPERCHOLESTEROLEMIC RAT MODEL

Hydrogen has emerged as a promising candidate due to its antioxidant properties and potential to modulate electron flow, enhancing mitochondrial energy metabolism and reducing oxidative stress. In this study, hypercholesterolemia male Wistar rats were utilized to investigate the safety and efficacy of intravenous hydrogen nanobubble solution (HNB). The study assessed serum lipid levels, complete blood count, and organ health following HNB administration compared to positive (simvastatin) and negative controls. Bayesian statistics were used to validate the findings. The administration of HNB did not adversely affect the immediate survival of the rats on a high fat diet (HFD), whereas simvastatin significantly reduced survival rates. It showed a dose dependent immunomodulatory effect, reducing white blood cell, lymphocyte, and monocyte counts. It also influenced erythropoiesis, as indicated by increased red blood cell counts and hemoglobin levels. A significant elevation in platelet counts was observed, suggesting potential effects on platelet production or lifespan. The study also noted changes in liver enzyme levels, with HNB indicating potential hepatoprotective effects. Furthermore, HNB treatment decrease in mean fat droplet count, suggesting a mitigation of diet induced hepatic steatosis. The findings suggest that HNB may serve as a protective agent against the deleterious effects of a high-fat diet, offering immunomodulatory and hepatoprotective benefits. This study provides a foundation for considering HNB as a potential therapeutic intervention for hypercholesterolemia and warrants further investigation into the long-term impacts of nanobubble treatment on diet induced pathologies. The consistency of results across traditional statistical significance and Bayesian evidence strengthens the validity of the observed treatment-specific effects.

Overlooked in-situ sulfur disproportionation fuels dissimilatory nitrate reduction to ammonium in sulfur-based system: Novel insight of nitrogen recovery

Sulfur-based denitrification is a promising technology in treatments of nitrate-contaminated wastewaters. However, due to weak bioavailability and electron-donating capability of elemental sulfur, its sulfur-to-nitrate ratio has long been low, limiting the support for dissimilatory nitrate reduction to ammonium (DNRA) process. Using a long-term sulfur-packed reactor, we demonstrate here for the first time that DNRA in sulfur-based system is not negligible, but rather contributes a remarkable 40.5 %–61.1 % of the total nitrate biotransformation for ammonium production. Through combination of kinetic experiments, electron flow analysis, 16S rRNA amplicon, and microbial network succession, we unveil a cryptic in-situ sulfur disproportionation (SDP) process which significantly facilitates DNRA via enhancing mass transfer and multiplying 86.7–210.9 % of bioavailable electrons. Metagenome assembly and single-copy gene phylogenetic analysis elucidate the abundant genomes, including uc_VadinHA17, PHOS-HE36, JALNZU01, Thiobacillus, and Rubrivivax, harboring complete genes for ammonification. Notably, a unique group of self-SDP-coupled DNRA microorganism was identified. This study unravels a previously concealed fate of DNRA, which highlights the tremendous potential for ammonium recovery and greenhouse gas mitigation. Discovery of a new coupling between nitrogen and sulfur cycles underscores great revision needs of sulfur-driven denitrification technology.

Definition of Regulatory Targets for Electricity Default Rate in Brazil: Proposition of a Fuzzy Inference-Based Model

The current electricity default rates in continental countries, such as Brazil, pose risks to the economic stability and investment capabilities of distribution utilities. This situation results in higher electricity tariffs for regular customers. From a regulatory perspective, the key issue regarding this challenge is devising incentive mechanisms that reward distribution utilities for their operational and investment choices, aiming to mitigate or decrease electricity non-payment rates and avoid tariff increases for regular customers. Despite adhering to the principles of incentive regulation, the Brazilian Electricity Regulatory Agency (ANEEL) uses a methodological approach to define regulatory targets for electricity defaults tied to econometric models developed to determine targets to combat electricity non-technical losses (NTLs). This methodology has been widely criticized by electricity distribution utilities and academics because it includes many ad hoc steps and fails to consider the components that capture the specificities and heterogeneity of distribution utilities. This study proposes a fuzzy inference-based model for defining regulatory default targets built independently of the current methodological approach adopted by ANEEL and aligned with the principles of incentive regulation. An empirical study focusing on the residential class of electricity consumption demonstrated that it is possible to adopt a specific methodology for determining regulatory default targets and that the fuzzy inference approach can meet the necessary premises to ensure that the principles of incentive regulation and the establishment of regulatory targets are consistent with the reality of each electricity distribution utility.

Techno-economic analysis of a grid/fuel cell/PV/electrolyzer system for hydrogen and electricity production in the countries of African and Malagasy council for higher education (CAMES)

The current electricity challenges in Africa have spurred the interest of governments in incorporating renewable energy sources into the energy mix. The use of hybrid solar energy systems has become a practical choice for electrification. The novelty of the paper is threefold: (i) The Grid/Fuel Cell/PV/Electrolyzer hybrid system is modeled, simulated, and optimized in for some communities of the nineteen countries of the African and Malagasy Council for Higher Education (CAMES) for the very first time; (ii) The levelized costs of hydrogen and energy were evaluated and compared; (iii) PV, fuel cell, grid purchases, and grid sales power productions were determined and compared. The study findings showed a levelized cost of energy varying between US$ 0.238/kWh (in Madagascar) and US$ 0.344/kWh (in Gabon). Subsequently, among the West, Central, and East African countries of CAMES, Mali, Chad, and Burundi were the countries with the smallest LCOE respectively. Also, the levelized cost of hydrogen ranged between US$ 1.84/kg (in Madagascar) and US$ 2.17/kg (in Gabon and Equatorial Guinea). The computation of the net present cost indicated a variation between 183,536 US$ (in Madagascar) and 216,115 US$ (in Gabon). The PV, fuel cell, grid purchases, and grid sales power productions were between 34,044 kWh/year (in Gabon) and 53,176 kWh/year (in Mali) for PV productions; between 43,526 kWh/year (in the Democratic Republic of Congo) and 43,784 kWh/year (in Chad) for fuel cell productions; between 29,976 kWh/year (in Senegal) and 30,700 kWh/year (in the Congo Republic) for grid purchases power productions; and between 11,604 kWh/year (in Gabon) and 29,608 kWh/year (in Mali) for grid sales productions respectively. It was concluded that the PV power production was the highest power generated by the hybrid system when compared with fuel cell, grid sales, and grid purchases power productions. Concerning the PV penetration, it varied between 54.2 % (in Gabon) and 84.7 % (in Mali). The present work is aimed at decision-makers so that they become aware of the need to urgently develop the renewable energy sector in the countries for a successful energy transition in Africa.

Antibacterial mechanism of thermoultrasound combined with potassium sorbate against Pichia membranifaciens

The effect of the antimicrobial mechanism of ultrasound (US) in combination with heat (T) and potassium sorbate (PS) treatment on Pichia membranifaciens (P. membranifaciens) is investigated in this study. It is found that ultrasound combined with heat (thermoultrasound [TS]) exhibits a synergistic inactivation efficiency, and the combinations of US, T, and TS with PS also improve inactivation efficacy through reductions of 0.32 ± 0.02 log, 0.73 ± 0.04 log, and 4.50 ± 0.04 log in P. membranifaciens achieved using US + PS, T + PS, and TS + PS, respectively. Further, use of the TS + PS treatment leads to cytoplasmic leakage and a decrease in dehydrogenase activity, as well as a significant increase in cell membrane permeability, causing membrane depolarization and the inward flow of extracellular calcium ions. In addition, the cell membrane composition is detected by infrared spectroscopy, demonstrating that TS + PS treatment results in a decrease in lipid and protein content and an increase in phospholipid content in the cell membrane. Scanning and transmission electron microscopy reveals a deformed cell structure and damage to cell membrane integrity after TS + PS treatment. In addition, the expression of heat shock protein (Hsp82 and Hsp70) genes is shown to decrease after TS and TS + PS treatment compared to the T and T + PS treatment groups, indicating cellular homeostasis has been broken and cells are responding to the damage by activating the protective gene expression program.

Effects of Nitrate Assimilation in Leaves and Roots on Biomass Allocation and Drought Stress Responses in Poplar Seedlings

Knowledge of tree biomass allocation is fundamental for estimating forest acclimation and carbon stock for global changes in the future. Optimal partitioning theory (OPT) and allometric partitioning theory (APT) are two major patterns of biomass allocation, and occurrences have been tested on taxonomical, ontogenetic, geographic and environmental scales, showing conflicting results and unclear ecophysiological mechanisms. Here, we examine the biomass allocation patterns of two young poplar (Populus) clones varying greatly in drought resistance under different soil water and nitrogen availabilities and the major physiological processes involved in biomass partitioning. We found that Biyu, a drought-sensitive hybrid poplar clone, had significant relations among biomass of leaf, stem and root, showing allometric partitioning. Xiaoye, a drought-tolerant poplar clone native to semi-arid areas, on the contrary, showed tightly regulated biomass allocation following optimal partitioning theory. Biyu had higher nitrate reductase activity in the fine roots, while Xiaoye had higher nitrate reductase activity in the leaves. Biochemical analyses and measurements of fluorescence and gas exchange showed that Xiaoye maintained more stable chloroplast membranes and photosystem electron flow, showing higher water use efficiency and a higher resistance to drought. A nitrogen addition could improve leaf photosynthesis and growth both in Biyu and Xiaoye seedlings under drought conditions. We concluded that the two poplar clones showed different biomass allocation patterns and suggest that the site of nitrate assimilation may play a role in biomass partitioning under varying water and nitrogen availabilities.

Long-Term Changes in Water and Ion Flows of the Pechora River, the Longest Full-Water European Arctic River

Long-term series of annual and seasonal water flow and major ions in the Pechora River were analyzed. Long-term phases of increased and decreased water flow were identified, ranging in duration from 11 to 49 years, and the major characteristics of these phases were determined. Changes in the sequence and boundaries of contrast phases in the annual and snowmelt spring–summer flood runoff were found to coincide. The difference between the mean seasonal water runoff during the phases of increased and decreased flow varied from 12 to 41%. The ion flow values of contrast phases typically differed by 9 to 36%, which is less than for water flow. This is due to the inverse dependence between ion concentrations and water discharge. Such peculiar negative feedback stabilizes the rates of chemical denudation in the river catchments to some extent and, thus, the discharge of major ions into seas, even during significant variations in water.

Inhibitory mechanism of Cr(VI) on sulfur-based denitrification: Bio-toxicity, bio-electron characteristics, and microbial evolution

Sulfur-based denitrification is a promising technology for efficient nitrogen removal in low-carbon wastewater, while it is easily affected by toxic substances. This study revealed the inhibitory mechanism of Cr(VI) on thiosulfate-based denitrification, including bio-toxicity and bio-electron characteristics response. The activity of nitrite reductase (NIR) was more sensitive to Cr(VI) than that of nitrate reductase (NAR), and NIR was inhibited by 21.32 % and 19.86 % under 5 and 10 mg/L Cr(VI), resulting in 10.12 and 15.62 mg/L of NO2--N accumulation. The biofilm intercepted 36.57 % of chromium extracellularly by increasing 25.78 % of extracellular polymeric substances, thereby protecting microbes from bio-toxicity under 5 mg/L Cr(VI). However, it was unable to resist 20–30 mg/L of Cr(VI) bio-toxicity as 19.95 and 14.29 mg Cr/(g volatile suspended solids) invaded intracellularly, inducing the accumulation of reactive oxygen species by 165.98 % and 169.12 %, which triggered microbial oxidative-stress and damaged the cells. In terms of electron transfer, S2O32- oxidation was inhibited, and parts of electrons were redirected intracellularly to maintain microbial activity, resulting in insufficient electron donors. Meanwhile, the contents of flavin adenine dinucleotide and cytochrome c decreased under 5–30 mg/L Cr(VI), reducing the electron acquisition rate of denitrification. Thermomonas (the dominant genus) possessed denitrification and Cr(VI) resistance abilities, playing an important role in antioxidant stress and biofilm formation. Environmental ImplicationSulfur-based denitrification (SBD) is a promising method for nitrate removal in low-carbon wastewater, while toxic heavy metals such as Cr(VI) negatively impair denitrification. This study elucidated Cr(VI) inhibitory mechanisms on SBD, including bio-toxicity response, bio-electron characteristics, and microbial community structure. Higher concentrations Cr(VI) led to intracellular invasion and oxidative stress, evidenced by ROS accumulation. Moreover, Cr(VI) disrupted electron flow by inhibiting thiosulfate oxidation and affecting electron acquisition by denitrifying enzymes. This study provided valuable insights into Cr(VI) toxicity, which is of great significance for improving wastewater treatment technologies and maintaining efficient and stable operation of SBD in the face of complex environmental challenges.

Fresh electricity business cold chain logistics development and countermeasures research

Under the background of new retail, fresh electricity business as a rising star of electricity business is developing rapidly, how to improve the service quality of fresh cold chain logistics, transportation efficiency, and further improve the market competitiveness of fresh cold chain logistics industry has gradually become the focus of attention. This paper expounds the necessity of the development of fresh electricity logistics, analyzes the main problems in the development of fresh cold chain logistics, the current fresh electricity cold chain logistics development strategy, how to promote the green and healthy development of fresh electricity cold chain logistics to provide countermeasures.